Stable- and some radioisotope-labeled compounds have been synthesized to support other laboratory projects. Structural analogues of.l-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) have been prepared for animal testing. 2H and 15N isotopomers of S-N-methylaminoalanine have been synthesized. Methods suitable for the selective sulfation of phenols in the presence of alcohols are under study.